Bifocal-lens grinder.



mete r? To all maycortcern;

Be ittk nown that 1, JOHN E. .GRAnssLE,-a

citizen Qfi'th United; States, residing at De troit; in the county of ayne, State of Michigan, have invented certain new and useful Improvements in Bifocal-Lens Grinders; and

and exact description of the invention, such as will enable others skilledinf the art :to, which it appertains to makeand use the same, refereneef "being bad. to I the accompanying drawings-t and to I the figures ofg'reference' marked.:thereon,:which form a part of this specificationpw-w; .e 1 Thisi ventionrelates to new and useful improvements in machines for grindin bevel o l-bifocal lenses; for the purpose %pre-u paring one lens for; the fitting of the other lens tluereon, and consists in the construc tion and arrangement of parts hereinafter intheclaims. r

The ObjOhOfethe inventionis to :produce a machine-for the purpose stated, wherein the arrangement is s .uoh-as to enable the fully set forth and pointed out particularly:

grinding'ofithee-bevelu on both sides of the lens from one. side of t estone or rindingwheel; t the same time enabling bot bevels to be ground exactlyzalike and in the are of a perfectcircle. K-

; 1 a =t The above object is. attained] by the mechanism illustrated in the accompanying drawing, in which:

Figure 1., is anelevation of a machine involving my invention; :Fig. 2i's a planview thereo Fig, .3 is adetail in end elevation of the pivotall .mountedgsupporting. sleeve on. Fig.4 is a longitudinal section as, on.

andthe reversi le lens holder mounted thereline 44-,of Fig. 2, a segment-0f the grinding wheel appearingin elevation. Fig.1 5yis a perspectiveview of a regulati ,-disk,1 the purpose of ,which will be hereinafter ex'-- lained.) ,Fig. 6 is a transverse sectionas on ine 6 -6 fFig.,2.-,

Referring to the characters, of reference, 1 designatesthe grinding wheel of suitable composition rnount-ed upon a shaft- 2- carry; mg the belt;p'i1lley 3-; driven from any suitab e source otpower through the medium of the belt 4 1.

Upon the mounted a support 1 ,6 in the form of a cone truncatedupon a llinetobli uely to the axis thereof, forming an inclined bearing face to which the forward end of the oarrlageilis to ess DETRO T. IC IG Nt atten:teasesitib e;;

the

i .seieeificatioaef netters ea ,Patented May 21,1907. Application-liled'i me26,1905. Serial No. 266,974.-

pivoted by means of the bolt 8', causing the v free end-of. said carriage to extend upwardly and rearwardly'at an incline; 'Ihis arrangevment enables the free end of the carriage to swing in the arc of acircle concentriowith the I pivot bolt 8',- as shown by dotted lines in Fig, 2. I do declare the following to .be a full, clear,

Pivotallyattached to the opposite edges qof-the carriage 7 by means of thes'et screws 9 which pass through the lower ends thereof, are the bifurcated links, 10 and '11- which stand'parallel to-each other and whose upper ends are'pivoted at 12-to the opposite sides of the two-part sleeve 13, formed of semlcylindrical upper and lower halves united by thescrew bolts 14 which pass through the margins thereof, whereby said sleeve be- I comes mounted upon the carriage 7 to swing longitudinally in the arc of acircle but is always maintained parallel with said carriage.

I Journal'ed to rotate within the sleeve 13 is a hollow shaft 15 having an extended table 16at its lower end. provided with the outwardly curved branchesl? carrying at their To comtable 16-with its stop. pins 18.are a part, there is employed a longitudinally movable plunger" 20 seated in the lower end of the hollow shaft 15. and having extending fromthe upper end thereof a rod 21- surrounded for a portion of its length byva coiled spring 22 confined between a pin 23 projecting from said rod near its lower end and the upper terminal: of the I larger bore in said shaft in which said spring, 7 is located. The extreme upperv end ofthe rod 22 passesthrough the upper end of said ,shaftand .is threaded to. receive the knurled adjusting .nut 24, ,whereby the tension of the spring 22 may be. regulated, said nut also serving as a means for drawing the rod and. plunger upwardly for the purpose of placing:

a lens in the holder or removing it there- 4 from. r

'It -will be noted that the tension of vthe spring 22 is normally exerted to; force the. .plunger,-.20 downwardly against the lens I 405 u the one side and, the stop pins 18on the other. i a Sid'e; the lower.end of the ,lungerbeing. table orrbed 5 of, the maoh neis which is firmly heldbetween said plunger on no tohed, as shownat 25, to em racethe edge 4 o ends the stop p1ns 18, agalnst which the ends r of the lens 19 are adapted to bear. deplete the lens holder of which the extended of the lens. By this arrangement the lens is i firmly held in place and maybe presented to no the face of the grinding wheel so as to grind the desired bevel on the margins of the con-rm caved opening 26 therein, the incline at g *which the lens is presented to the face of the grinding wheel determining the extent of the. evel and the swinging movement of the carnage upon the fulcrum 8 enablin said concaved opening to be ground in the arc of a circle concentric with said fulcrum.

Through the rotary movement of the shaft the opposite margins or edges of the concave of the lens may be in succession presented to the face of the grinding wheel by makcarried in the holder so as to posite sides to the grinding wheel for the purpose of beveling from the opposite sides the margin'of the concaved opening therein.

To look the shaft so as to hold thelens-in proper relationto'the grinding wheel, the upper link 11 is provided with an, arm 29 whose ends project in opposite directions at right angles to said link and whose upper end is 3 tion to present the lens to the face of the When withdrawing the lens from contact adapted to engage in one ofthe notches in the disk 27, when the.

lens holder is in posigrinding wheel, as shown in Figs. 1, 2 and 4.

"with the wheel by swinging the holding .sleeve upwardly upontlie links 10 and 11, the

, tilting of link 11 willcarry the arm from the lower notch in the disk, asshown by dotted lines in Fig. .1, thereby releasing the rotary shaft and enabling it to be turned to reverse the lens, the shaft being again locked, as the holding sleeve is swung downwardly to again present thelensto the wheel, by the entrance of the upper end of the arm 29,into the opposite notchof the disk 27.

In order to prevent the lens holder from swinging downwardly too far against the grinding wheel, an adjusting screw 30 is employed which passes through the carriage 7.

and engages the under face of a rotatable disk 31 secured to the lower end of. the arm 29. Upon the under face of said disk, as shown in Fig. 5, are steps 32 in different planes which by the rotation of the disk, may be brought into alinement with the upper end ofthe adjusting screw 30, thereby regulating the downward movement. of the lens holder toward the'grinding wheel in accordance with the concave in the lens being ground. By means of this arrangement, it will now be seen that the concave in a bifocal lens may be beveled on opposite sides to allow of the fitting of another lens of different focus therein without changing the lens' holder to the -opposite side of the grinding wheel as has heretofore been necessary, the opposite bevsaid carriage,a present its op' riage to Letters Patent is:-

1. .In a bifocal lens grinder, the combina tion with a suitable grinding wheel, ofa movable carriage, a lens holder mounted on'the carriage and movable to present the lens to the grinder, means for reversing the holder to present both sides of the lens to the grinding wheel, and means for automatically locking the wheel as the carriage moves into the grinding position.

\2. In a bifocal lens grinder, the combination with a grinding wheel, of a movably. mounted carria e pivoted links supporting Iens holder on said carriage positioned to present the lens at an acute angle to the wheel, and means for reversing said older to present both sides of the lens for grinding.

7 3. In a bifocal lens grinder, the combination with a grinding wheel, of a carriage movable in the arc of a circle, a lens holder 'upon said carria e, said holder being movable toward and om the Iinding wheel, and rotatable to present bot sides of the lens to said wheel and means for automatically locking the wheel as the carriage moves forward to present the lens to the grinding wheel.

4. In a bifocal lens grinder, the combination with a suitable grinding wheel, of a carriage movable in the arc of a circle, a springactuated lens holder mounted-on said carpresent the lens at a tangent to the periphery of the wheel, and means for reversing the older to enable the grinding of a .bevel on opposite sides of the lens.

5. In a bifocal lens grinder, the combination with the grinding wheel, of a carriage pivotally mounted in a plane tangent to the periphery of the wheel, a lens holder mounted on said carriage and movable independently thereof, means for retaining the lens in position while being ground, and means for presenting the lens to the stone to grind the opposite bevels thereon without, changing the lens in the holder.

6. The combination with a grinding wheel, of a carriage movable in the arc of a circle adj acent said wheel, a lens holder upon the carriage movable toward and from the grinder,

said lens holder being reversible to present the opposite sides of the lens for grinding, a spring-actuated plunger adapted to engage said lens and means forlocking the lens holder during the operation of grinding.

In testimony whereof, I sign this specification in the presence of two witnesses.

JOHN E. GRAESSLE. Witnesses:

E. L. RICE, C..E. NORMAN. 

